Railroad car retarder system



Feb. 8, 1966 B. G. GALLACHER 3,234,378

RAILROAD CAR RETARDER SYSTEM Filed Feb. 13. 1961 l2 Sheets-Sheet 1 RNE?, mm

Feb. 8, 1966 B. G. GALL/CHER 3,234,373

RAILROAD CAR RETARDER SYSTEM Filed Feb. 15.' 1961 2 sheets-sheet a 25 2 5 23 Q' i@ i 21 z y I 24 l 25' i I o5 l :o E

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32L f3! G O i .J 3 5- .33 fij 24J mJVENToR: @XI/@M420 6AM/16H5@ United States Patent O 3,234,378 RALROAD CAR RETARDER SYSTEM Barnard G. Galiacher, 945 Liberty Ave., El Cerrito, Calif. Filed F eb. 13, 1961, Ser. N0. 88,779 4 Claims. (Cl. 246-182) This invention relates lto and in general has for its object the provision in a railroad classiiication yard of a retarder system for reducing and substantially equalizing the velocities of cars having different rolling characteristics, and which have been humped and classiied as to destination, by the time that said cars have reached their coupling points.

AS railroad -freight trains move along a railroad, it is necessary at yards, usually at junctions, to disassemble the trains into cars and groups of cars by destination, and to later reassemble each group of cars destined to `a common point into a new train. Outbound trains often contain up to l and more groups or blocks of cars in station order, so that the blocks are set out progressively at the designated stations as the train -progresses along the line.

At the present time, at many of the major terminals and junction points there are in operation what are known as retarder yards. In these yards an entire incoming train is shoved by a switch engine at a uniform speed of about 2 mph. over an artificial Ihump or crest, which is is usually i7 to 20 -feet high. As cars reach the crest, they are cut ott one by one or in groups of up to three cars and allowed to descend by gravity to one of many classification tracks. The number of classification tracks in a major retarder yard normally runs from 24 to 84. Because of the difference in the resistance or rollabiiity ot the cars, most cars have to be slowed down as they descend the hump under gravity. This is done by heavy steel castings and appurtenances known as retarders, which are attached to the track and rub against the sides of the wheels to slow the cars down. The degree of pressure of the retarders against the wheels is controlled (l) manually by one of several retarder operators, or (2) by electronic computer. in the latter case, the acceleration of the car on a known uniform grade is observed by radar. rfhe acceleration is an index of the rolling resistance of the car. This and other pertinent factors are fed into the electronic computer, which computes the theoretical release speed from the last retarder, and the retarders are controlled by the electronics to release the car at this speed. This operation must be overseen by a retarder operator.

At other than major terminals, trains are lbroken up into the various classications by what is known as atswitching. In flat-switching, a switch engine shoves a train or group of cars -down a iiat lead or ladder track at speeds of 2 to 8 mph. A switchman walks or runs alongside the head end of the train, and at the proper time uncouples a car or several cars, which are then allowed to roll by their momentum into a classiiication track. The switch engine then reverses direction, pulls the whole train back a distance up -to several hundred feet, and the process is repeated until the entire train is broken up or classiiied. The switches from the lead to the classication tracks are hand-thrown by switchmen. This is a very ineiiicient, expensive, and timeconsuming operation.

The major retarder yards iirst referred to are generally satisfactory, but because of their extreme expense, most of which is concentrated in the retarders, radar, and computers at the hump and which is not proportional to the number of classification tracks, are not justiiied for small classification yards. Their cost can be justified 3,234,373 Patented Feb. 8, 1966 only at major terminals that switch 1200 cars or more per day. Another consideration is that in existing major retarder yards, the cars frequently couple into each other as they roll along the classiiication tracks under gravity at speeds that are damaging to cars and lading.

On the other hand, dat-switching operations at other than major yards is unsatisfactory for the reasons previously mentioned.

There is thus a definite need by the railroads for a small, inexpensive2 automatic classification yard at points where a major retarder yard cannot be justied because of the high initial cost. The object of this invention is the design of an automatic classilcation yard that is inexpensive, automatic, land in which cars will couple at speeds not to exceed 4 mph.

More speciiically the object of this invention is the provision in a classification yard of classification tracks, each including: a trst section 'having a negative grade and arranged to receive bumped classiied cars; normally closed, elongated car retarder means located adjacent a portion of said first section intermediate the ends thereof -for stopping a car at some point within the length of said retarder means, depending upon the momentum of said car; and means for then opening said retarder means so that said car, starting from a standstill, can continue its travel over said first track section under the iniluence of gravity (a momentum depending upon the point at which it was stopped on said first track section).

Another object of my invention is the provision of a car retarder system of the character above set forth wherein the track section portion stradd'led by the car retarder is made up of an upstream lsubsection and a downstream subsection, and wherein the upstream subsection has a greater negative grade than the downstream subsection.

Still another object of this invention is the provision of a car retarder system of the character above described, including: a track section having a negative grade, a car retarder straddling a portion of 'said track section intermediate the ends thereon; biasing means for biasing said car retarder to a normally closed position; opening means for opening said car retarder; sensing mean-s for sensing the passage of la car on said track past a predetermined point upstream of said car retarder; time delay means under the control ot said sensing means lfor actuating said opening means; and means responsive to the presence of a car within said car ret-arder for hold-ing said car retarder in its `open position so long as a car is disposed within said car retarder.

rPhe invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description Where that form of the invention which has been selected for illustration in the drawings accompanying and forming `a part of the present speciiication is outlined in full. In said drawings, one form ot the invention is shown, but it is to be understood that it is not limited to such form, since the invention as set forth in the claims may be embodied in other forms.

Referring to the drawings:

FIG. 1 is a diagrammatic plan view of a classification yard embodying the objects of my invention.

FIG. 2 is a track and velocity prot-lle of the uppermost track shown 4in FK?. l and which embodies the objects of my invention.

FG. 2A is a continuation of the grade proiile curve of FIG. 2.

FIG. 3 is a diagram showing the one pair of normally closed car retarders operatively associated with one rail of my system and the control circuits for opening and closing the retarders at the required time.

FIG. 4 is a section taken on the section line 4 4 of FIG. 3 diagrammatically showing the retarder means of my invention in end view and in which its hydraulic system has likewise been diagrammatically illustrated.

FIG. is an end view of the car wheel flange contactor switch or memory device used for controlling the electric circuit of my system, and which in turn controls the retarder hydraulic system, one track rail being shown in section.

llustrated in FiG. l is a classiiication yard for disassembling a train into cars and/or groups of cars by destination, and which as viewed in plan is of more or less typical conguration. However, and as illustrated in FIG. 2, the track proiiles of the system, particularly with respect to the rst track section above referred to, do not necessarily conform with conventional profiles.

The system as illustrated in FlGS. 1 and 2 includes a main track 1 arranged to pass over an artiiicial hump or crest 2 which conveniently may be in the order of 8 feet above the floor of the classification yard. Here it might be observed that in FIG. l the track 1, as well as other tracks presently to be described, is indicated by a single line, although it consists, as usual, of a pair of rails.

Diverging from the track Il through switching means 3 are a pair of first classification tracks 4 and 4a. Each of the tracks 4 and 4a similarly diverges through switch means 5 located at or beyond the clear point of the latter tracks into classification tracks 6 and 6a, and each of these tracks diverges through switch means 7 into classication tracks S and da. Here it might be observed that the clear point or" each pair of diverging tracks is that point at which a car on one such track will clear an adjacent car on the other track, and that the pattern of the various classiiication tracks is symmetrical about' a line containing the main track il. Diverging from each of the tracks S and da through switch means 9 on each side of the center line of the track l are parallel classification tracks it?. As a result of this construction it will be noted that the main line 1, together with each of the classification tracks 4, 6, 8 and lil, makes up eight tracks or lines 11 through 18 symmetrically disposed about the center line of the track ll.

Straddling each rail of track l@ is a car retarder assembly generally referred to by the reference letter R, and located upstream of each retarder assembly is a rail contactor generally referred to by the reference letter C.

Each of the tracks or lines lli-1S is so graded that it has a profile such as, for example, generally indicated in FIG. 2 by the line GP. As shown in FIG. 2, for purposes of illustration the track 1 on the left-hand side of the hump 2 has a grade of -}-l.5%, and the hump 2 on its right-hand side has a grade of This latter grade is maintained through the tracks 4 and o and up to the switch 7. From this point on up to the upstream side of the retarder assembly R the classification tracks 8 and 10 have a grade of 1.0%- As will be presently more fully described, each retarder assembly is made in two sections arranged in tandem. That portion of the track 10 passing through the irst or upstream section of the retarder assembly has a 1.2% grade, whereas that portion ot the track passing through the downstream section of the retarder has a 1.0% grade. Beyond the retarder R, each track 10 has a section having a 0.2% grade merging with a section having an even slighter grade of 0.12% and which in turn, and as illustrated in FIG. 2A, merges with a nal track section'having a slight positive grade in the order of +0.30% but insutiicient to cause a car to reverse its direction of travel.

1n FIG. 2, the curve VPl is a velocity proiile of a hard roller car traveling over the track line 11 (uppermost line of FIG. l) under the influence of gravity after it has been humped over the hump or crest 2 at a speed of 1.7 mph. Similarly, Vig is a velocity proiile or a medium roller car and VP3 is a velocity proile of an easy roller or heavy car starting over the hump 2 at Retarder assemby As diagrammatically illustrated in FIG. 4, each retarder R includes a pair of opposed, outwardly extending fulcrurn bars 2l and 22 fixed to each rail 23 of one of the tracks in question. Pivoted to the outer end of each of the bars 2i and 22 is a tirst-class lever 24 having legs 25 and 26. Fixed to the upper end of each leg 25 in parallelism with the rail 23 is an elongated shoe 27 arranged in the closed position of the device to frictionally engage one side of a car wheel 28. Fixed to and extending between the legs 26 intermediate their ends is a heavy compression spring 29 arranged to bias the shoes 27 to their closed positions against the car wheel 28. Disposed between the outer ends of the legs 26 is a hydraulic cylinder 31 including a pair of pistons 32 and 33, each provided with an outwardly extending stem connected to one of the legs 26. Connecting the opposed ends of the cylinder 3i to a hydraulic line 3d are branch lines 35 and 3d. Under the influence of pressure in the line 34, the legs 26 are moved inwardly, thereby reieasing the shoes 27 from the wheel 23. Upon release of the pressure in the line 34, the spring 29 serves to bring the shoes 27 into braking engagement with the sides of the car wheel 28.

Conveniently, each of the shoes 27 can be made of two 39-ioot sections of railroad rail connected together in tandem, and preferably each roll of each track should be provided with a retarder assembly of this type so that each side of each car will be uniformly braked and several hydraulic actuators should be spaced along the length or each retarder assembly so as to continuously subject the car wheels to a uniform braking action as they traverse the length of the retarder assembly.

As illustrated in FG. 3, the hydraulic line 34 communicates through a control valve 37 and a flow line 38 with a pump 39, which in turn communicates through a line 4l with a reservoir 42. Also connected to the control valve 37 is a return tiow line communicating with the reservoir 42. The control valve 37 is under the control of an operatively associated solenoid 43 and is procurable on the open market from Union Switch & Signal Co. of Swissvale, Pennsylvania, as a Type C Solenoid and Control Valve.

By means of the hydraulic circuit above described, each retarder assembly can be left in its normally closed position under the iniiuence of its spring 29, or it can be periodically held in its open position under the influence of the solenoid 43.

As diagrammatically indicated in FIG. 3, the free ends 27a of the shoes 27 should be outwardly iiared so as to form a reentrant angle for the reception of a car wheel.

The retarder assemblies associated with each track should he located approximately 10() feet downstream on this track relative to the upstream clear point.

Flange conrector assembly C The 'lange contacter assembly C associated with each track should be located approximately 50 feet upstream of the upstream ends of the tracks retarder assemblies.

As illustrated in FIG. 5, each such assembly includes a Silec contactor or switch 51 provided with a single spring-biased actuating arm 52 arranged to be depressed by the passage of a car wheel 28 over one of the track rails 23 and so open the switch Si. To this end the switch 5l is supported at the proper height by brackets 53 mounted on a base S4 and the base is fastened to the foot of the rail 23 by clamps 55. Siiec rail contactors are patented devices procurable from Transcontrol Corp. of Port Washington, New York, although manufactured by Silec Cie, of Paris, France.

Electrical control assembly Associated with the ange contacter assembly C and the retarder assembly R is an electric control system or assembly generally referred to in FIG. 3 by the reference letters ES.

Included in this assembly is a relay switch 61 controlled by the contacter switch 51 through aline 62. The switch 61, in turn, controls a time delay relay switch 63 through a line 64. Conveniently, Ithe switch 63 .is set to close about 16 seconds after the switch 51 has opened under the influence of a car passing over the switch arm 52. Connecting the relay 63 with a retarder lcontrol relay 65 is a relay 66 and a line 67, and connecting the relay 65 with the solenoid 43 is a line 7S.

Both rails of that portion of the track 11 straddled by the shoes 27 of the retarder assemblies R are insulated as at 69 and 71 from the upand downstream portions of the track 11. Connected to the two rails of the insulated portion ot the track 11 are lines 72 and 73 connected to the relay 66 and which serve to de-energize this relay when the lines 72 and 73 are shorted out by the presence ot a car within the retarder zone. The relay 66, insofar as the relay 63 and the line 67 are concerned, merely serves as a closure switch, but is otherwise independent of the relay 63, and, as above stated, is de-energized only in response to the presence of a car in the retarder zone.

Now assuming that there is no car in the retarder zone, and that a car passes over the switch arm 52. This opens the switch 51 and de-energizes the relay 61. The relay 61, de-energ-ized, closes the line 64, and as a consequence the time delay relay 63 is energized and serves to close the line 67 and so energize the retarder control relay 65. The latter relay closes the line 78, and this in turn energizes the solenoid 43, and as a result the retarder assembles are forced to their open positions by the hydraulic system. However, and as above noted, this occurs 16 seconds after the car in question has depressed the switch arm 52. In the meantime this car has entered the retarder zone and has been brought to a dead stop somewhere within the 78-foot length of the normally closed retarder shoes, depending upon the inertia of the car when it enters the retarder Zone.

Following this, and at the end ofthe 16-second interval, the relay 63 energizes the solenoid 43, and as a `consequence the hydraulic cylinder 31 is pressurized and the retarder shoes 27 are forced -to -their open position. However, sometimes instead of sending single cars through the retarder zone, it is desirable to send two or three coupled cars through this zone. In this event it is essential that the retarder shoes be held in their open posi-tion until all of the cars which have been previously brought to a stop in the retarder zone have cleared this zone. To insure this, the relay 66, acting independently of the relay 63, functions to maintain the retarder control relay 65 energized ,so long as the lines 72 and 73 are connected through any car disposed within the insulated retarder zone. Once all cars have cleared the retarder zone, contact between lines 72 and 73 is broken, the relay 66 is energized, and the relay 65 and the solenoid 43 are de-energized. The valve 37 then connects the hydraulic line 34 with the hydraulic reservoir 42 to thus relieve the pressure in the cylinder 31 and the springs 29 return the retarder shoes 27 to their closed positions, ready to receive the wheels of another car or group of cars.

The relays 61, 65 and 66 are standard relay switches obtainable from the Union Switch & Signal Co. under the name Control Relay Type DN-ll. The time delay relay 63 is a standard item obtainable from General Railway Signal Co. as Type KB.

Operation As a result of the system above described, each car or lgroup of coupled cars is bumped over the hump 2 at a given speed. The momentum or inertia of each car entering any given retarder zone depends upon its rollability. The three velocity profiles of FIG. 2 show the velocity heads of an easy rolling (low resistance) car, a medium resistance car, and a high resistance car. The vertical distance of each velocity profile above the top of the rail prole represents the velocity head of the car at any point. The velocity head may be converted to speed by the equation:

where h represents the velocity head in feet, V represents velocity in feet per second, and g represents the acceleration due to gravity.

FIG. 2, by way of example, shows the speeds of cars at critical points.

From FIG. 2, and as above describe-d, it is Ito be noted that that portion of the track 10 straddled by the first or upstream section of the retarder assembly has a grade of 12%, and that the downstream section of the retarder straddles a portion of track having a lesser grade of -l.0%. The reason for this is that it is the hard rolling cars which are brought to a stop in the upstream section of the retarder, and to insure that when these cars are released they will continue ontheir way under the influence of gravity, this section of track is given a steeper inclination. The easy rolling cars are stopped on the downstream section of the retarder and, being easy rollers, do not need this additional inclination to again start rolling after they have been released. This dual inclination of the tracks within the retarder zone is a desirable precaution but not essential, for this entire section of track could be given such an inclination that cars of all types would start down the grade after being released.

It will therefore be appreciated that the hard rolling high resistance cars will be sorted automatically from the easy rollers in that the hard rollers will approach the retarders at low speed `and will be stopped at the upper end of the retarders. After being stopped and released, the hard rollers will have a considerable vertical distance to drop through and beyond the retarders, so they will roll a reasonable distance before they stop. On the other hand, it will take the entire length of both retarder sections (78 feet) to stop an easy (low resistance) roller, this car having attained a speed of more than 9 mph. approaching the retarder. When this car is stopped, then released, it will have only a short vertical distance to drop, and will therefore not attain a great speed, which is desirable. Coupling speed will thus be held to 4 m.p.h. or less and no damage to cars or contents will ensue. Medium resistance cars will be stopped between the top and bottom ends of :the retarder, and will have a medium vertical distance to drop after release from the retarder. Retarder will reclose in sufficient ytime to stop the next following car before it can couple into the rst car with a damaging impact. l

At the low end of the classication tracks (FIG. 2A), due to the low speeds involved, cars will be stopped by placing 400 feet of the end of the classification tracks on a +03 0% grade, upon which cars will not reverse themselves and roll back toward the hump and possibly collide with the following car. No skates or skatemen will be required as in major retarder yards. The grades enumerated cannot be placed in present major retarder yards because speeds of 9 to 10 m.p.h. must be protected against.

In major retarder yards, after cars are classied on the classification tracks, the cars are pulled by a trimmer or pull-down engine out the bottom end of the classification yard, as each classification track becomes full. In the small automatic classification yard above described, one hump engine can classify 400` cars in 4 to 5 hours and still leave enough time in an 8-hour shift to pull the groups of cars, as each classification track becomes full, from the classification tracks back over the hump, to a departure yard. Elimination of the need for a trimmer engine would be a distinct advantage.

Another unique advantage of this design is that the cost would be directly proportional to the number of classification tracks, and the cost per track of the retarders and control apparatus would be less than half the cost per track of the retarders and control apparatus for the present major type retarder yard.

Still another unique advantage of this system is that retardation and speed control is completely automatic, and no retarder operators are required, as at existing major retarder yards.

I claim:

1. A car retarder system comprising: a track having a crest, a track section extending from said crest to thereby define a direction, said section having a negative grade in said direction; normally closed braking means located adjacent said section for braking a car to a standstill at a point within said braking means; means connected with said braking means for opening said braking means after said car has been brought to a standstill Within said braking means; and means for then maintaining said brake in its open position until said car has cleared said braking means.

2. A structure such as set forth in claim 1 wherein said track section gradually merges at its downstream end with a terminal track section having a positive grade insufficient to permit a car only under the influence of gravity to roll towards said hump.

3. In a classification yard: a track provided with a hump and a track section extending from said hump to thereby define a direction, said section having a negative grade in said direction; an elongated car retarder straddling a portion of the length of said track section and operative to brake a car to a standstill within the length thereof; first means for resiliently holding said car retarder in its closed position; sensing means for sensing the presence of a car on said track section at a point in advance of said car retarder; time delay means under the control of said sensing means for opening said car retarder at a predetermined interval of time after said sensing means has sensed said car; and second means responsive to the presence of a car within the confines of said car retarder for holding said car retarder in its open position against the action of said holding means until said car has cleared said car retarder.

4. A structure of' the character set forth in claim 3 wherein said first biasing means is in the form of a spring; wherein said sensing means includes a first switch under the control of a switch arm located in the path of a car traversing said track section; wherein said time delay means includes a relay switch circuit under the control of said first switch, and wherein said second means includes a second normally open relay switch circuit arranged to be closed in response to the presence of a car within the confines of said car retarder.

References Cited by the Examiner UNITED STATES PATENTS 1,553,723 9/ 1925 Shepard 246-182 1,681,131 8/1928 Prescott.

2,727,138 12/1955 Agnew 246-182 2,814,996 12/1957 Albrighton 246-182 FOREIGN PATENTS 649,753 1/1951 Great Britain. 816,163 7/1959 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

LEO J. LEONNIG, LEO QUACKENBUSH, Examiners. 

1. A CAR RETARDER SYSTEM COMPRISING: A TRACK HAVING A CREST, A TRACK SECTION EXTENDING FROM SAID CREST TO THEREBY DEFINE A DIRECTION, SAID SECTION HAVING A NEGATIVE GRADE IN SAID DIRECTION; NORMALLY CLOSED BRAKING MEANS LOCATED ADJACENT SAID SECTION FOR BRAKING A CAR TO A STANDSTILL AT A POINT WITHIN SAID BRAKING MEANS; MEANS CONNECTED WITH SAID BRAKING MEANS FOR OPENING SAID BRAKING MEANS AFTER SAID CAR HAS BEEN BROUGHT TO A STANDSTILL WITHIN SAID BRAKING MEANS; AND MEANS FOR THEN MAINTAINING SAID BRAKE IN ITS OPEN POSITION UNTIL SAID CAR HAS CLEARED SAID BRAKING MEANS. 